When joining two thin metal sheets together with, e.g. rivets, there is often difficulty in achieving sufficient shear load strength. It is believed that the shear load strength can be increased by the order of 15% when a blind rivet is applied in a known manner to pre-dimpled sheets, that is sheets in which dimples have been pressed around holes formed to receive blind rivets. In many applications however it is not practical to press dimples into sheets before they are secured together.
It is an object of the present invention to provide a joining method and apparatus capable of providing increased joint shear load strength.